On an electronic commerce (EC) site such as an online shopping mall on which a plurality of stores open stores, each store registers product information on products that the store wants to sell, such as pictures, explanations, prices, and others of the products on the EC site, thereby creating pages of the products. For example. Patent Document 1 discloses an online shopping management device that receives and acquires product display information (product guide page) with contents created according to a display form for an online shop from a real store side, and opens an online shop corresponding to the real store.